Paul Tero is an experienced PHP programmer and server administrator. He developed the Stockashop ecommerce system in 2005 for Sensable Media. He now works part-time maintaining and developing Stockashop, and the rest of the time freelancing from a corner of his living room, and sleeping, eating, having fun, etc. He has also written numerous other open sourcish scripts and programs.

Have you ever come across a bit of JavaScript like $(".cta").click(function(){}) and thought, “What the $('#x') is that” If it looks like gibberish to you, then please read on. If you think that snippet of code couldn’t possibly be real, then please browse some jQuery examples. They are full of such constructions.

This article covers the key concepts that underly such intimidating fragments of code, but we’ll start with a longer example, based on an example for animating a square.

Imagine that you wake up one morning, reach groggily for your laptop and fire it up. You’ve just finished developing a brand new website and last night you were proudly clicking through the product list. The browser window is still open, the Widget 3000 is still sparkling in its AJAXy newness.

You grin like a new parent and expectantly click on “More details”. And nothing happens. You click again, still nothing. You press Refresh and get that annoying swirling icon and then the page goes blank. Help! The Internet is gone!

Imagine that you wake up one morning, reach groggily for your laptop and fire it up. You’ve just finished developing a brand new website and last night you were proudly clicking through the product list. The browser window is still open, the Widget 3000 is still sparkling in its AJAXy newness.

You grin like a new parent and expectantly click on “More details”. And nothing happens. You click again, still nothing. You press Refresh and get that annoying swirling icon and then the page goes blank. Help! The Internet is gone!

In the construction industry, a “firewall” is a specially-built wall designed to stop a fire from spreading between sections of a building. The term spread to other industries like car manufacturing, and in the late 1980s it made its way into computing.

On one side of the wall is the seething electronic chaos of the Internet. On the other side is your powerful but vulnerable Web server. These computer firewalls are actually more like fire doors because they have to let some stuff through.

This is a story that dates back to the earliest days of computers. The story has a plot, well, sort of. It has competition and intrigue, as well as traversing oodles of countries and languages. There is conflict and resolution, and a happyish ending.

But the main focus is the characters — 110,116 of them. By the end of the story, they will all find their own unique place in this world. This story will follow a few of those characters more closely, as they journey from Web server to browser, and back again. Along the way, you'll find out more about the history of characters, character sets, Unicode and UTF-8, and why question marks and odd accented characters sometimes show up in databases and text files.

At the heart of every modern Mac and Linux computer is the “terminal.” The terminal evolved from the text-based computer terminals of the 1960s and ’70s, which themselves replaced punch cards as the main way to interact with a computer. It’s also known as the command shell, or simply “shell.” Windows has one, too, but it’s called the “command prompt” and is descended from the MS-DOS of the 1980s.

Mac, Linux and Windows computers today are mainly controlled through user-friendly feature-rich graphical user interfaces (GUIs), with menus, scroll bars and drag-and-drop interfaces. But all of the basic stuff can still be accomplished by typing text commands into the terminal or command prompt. Using Finder or Explorer to open a folder is akin to the cd command (for “change directory”). Viewing the contents of a folder is like ls (short for “list,” or dir in Microsoft’s command prompt). And there are hundreds more for moving files, editing files, launching applications, manipulating images, backing up and restoring stuff, and much more.

Many Web companies spend hours and hours agonizing over the best domain names for their clients. They try to find a domain name that is relevant and appropriate, sounds professional yet is distinctive, is easy to spell and remember and read over the phone, looks good on business cards and is available as a dot-com.

Or else they spend thousands of dollars to purchase the one they really want, which just happened to be registered by a forward-thinking and hard-to-find squatter in 1998. They go through all that trouble with the domain name but neglect the rest of the URL, the element after the domain name. It, too, should be relevant, appropriate, professional, memorable, easy to spell and readable. And for the same reasons: to attract customers and improve in search ranking.

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